Expression of morphogenic genes in mature ovarian and testicular tissues: Potential stem‐cell niche markers and patterning factors

Abstract

Morphogens are developmental regulators that modulate different tissue patterning, proliferation, differentiation, or remodeling processes in embryonic and adult tissues. Morphogens may also evoke specific regulatory programs in stem cells. Some of the morphogens involved in these processes have been characterized, while others remain unidentified. A microarray containing 3,557 salmonid cDNAs was used to compare the transcriptomes of rainbow trout precocious ovary at three different stages during second year (June, August, and October) with a reference (June normal ovary) transcriptome. During this study, we detected morphogen transcript hybridizations to salmonid elements and the study was enlarged to investigate these activities in various developmental stages of both ovary and testis. Genes from diverse development regulator families such as Anterior gradient-2, BMP, Epimorphin, Flightless, Frizzled, Notch, Tiarin, Twisted gastrulation, and Wnt were demonstrated to be expressed in the adult trout gonads. In mice or rats, expression of mammalian bmp-4, epimorphin, flightless, twisted gastrulation, and GW112 transcripts were localized to cell types isolated from the developed ovary and testis. Comparisons of salmonid and mammalian morphogens at the amino acid residue level show high similarities, suggesting functional conservation. This report provides evidence for local regulation by various morphogens and their potential to control distinct programs of gene expression in the gametes and their accessory cells during gametogenesis.

Dynamic expression of bone morphogenetic protein 4 in reproductive organs of female mice

“…The significance of BMP signaling in the ovary is further highlighted by the increased ovulation rates in Booroola sheep with a point mutation in BMPR1B gene (Mulsant et al 2001, Souza et al 2001, Wilson et al 2001. Previous in situ hybridization and PCR-based studies have suggested that BMP4 is mainly synthesized in theca cells, corpus luteum, and other cells including stromal cells and acts in a paracrine manner to regulate granulosa cell function (Shimasaki et al 1999, Erickson & Shimasaki 2003, von Schalburg et al 2006, Abir et al 2008. Our previous report demonstrated that BMP4 promotes the transition of the primordial to primary follicle during follicular development (Tanwar et al 2007).…”

“…In contrast, BMP4 mRNA is reported to be expressed in both granulosa and thecal cells of bovine, chicken, and mouse ovary (Onagbesan et al 2003, Fatehi et al 2005, von Schalburg et al 2006. Recently, BMP4 protein was detected in oocytes and granulosa cells of human ovary (Abir et al 2008), while growth differentiation factor 9 (GDF9) and BMP15 expression appear to be limited to the oocyte of the follicles throughout follicular development (Bodensteiner et al 1999, Erickson & Shimasaki 2003, Juengel et al 2004) except in primates, where GDF9 is also expressed in the cumulus and mural granulosa cells (Duffy 2003).…”

Olfactomedin-4 Regulation by Estrogen in the Human Endometrium Requires Epidermal Growth Factor Signaling

“…Other authors have observed similar effects using colon cancer cells: OLFM-4 interfered with cytoskeleton filaments and caused cells to round up and detach. 9 OLFM-4 is particularly associated with tissues with high regenerative potential (ie, bone marrow, the gastrointestinal tract, prostate, murine ovaries, rat testis, 31 and endometrium). In addition, the fact that OLFM-4 affects processes such as cell adherence, cell-cell interaction, motility, and apoptosis, rather than proliferation, implies that this protein plays a determining role in differentiation of cells.…”

Wnt signaling promotes proliferation and stemness regulation of spermatogonial stem/progenitor cells

“…Although there are a few reports on the expression of the Fzs in rodent ovary and testis (Ricken et al 2002, Hsieh et al 2005, von Schalburg et al 2006, there is no evidence showing the expression of Fzs in human germ cells. We have isolated human germ cells from adult testis as explained in the materials and methods section.…”